Such devices for simultaneously applying force on several identically acting gas-exchange valves are generally known to those skilled in the art and do not have to be explained in more detail at this point. These devices are also used partially for shutting off or switching valve lifts.
In the devices noted above, a separate reservoir and high-pressure chamber is allocated to each pressure piston. The constant goal of further reducing the oscillating valve train masses, but also reducing installation space problems, etc., leads to the continuous miniaturization of such devices. Thus, the amount of hydraulic medium that can accumulate in the reservoir of the pressure piston necessarily decreases. In other words, the ratio of volumes of the reservoir to the high-pressure chamber becomes worse.
If the internal combustion engine with the valve train according to this type is shut down, then the reservoirs can empty. Here, the pressure pistons that are shut down at the point of valve lift are most at risk. When the internal combustion engine is turned on again and sufficient pressure has not yet built up in the hydraulic medium, not enough hydraulic medium is available for proper lash adjustment (for example, to move the element away from the blocked position) and thus rattling noises are generated.